This invention relates to a method of manufacturing an amorphous photovoltaic-cell module. More particularly, it relates to a method of manufacturing an amorphous photovoltaic-cell module in which a large number of amorphous photovoltaic cells are formed on a lower electrode of large area and put into a module, thereby to reduce the cost of manufacture.
FIGS. 5(a) and 5(b) are a front view and a sectional view, respectively, showing a conventional metal substrate type amorphous photovoltaic cell of 10 cm.times.10 cm which is employed in an amorphous photovoltaic-cell module for, e.g., the generation of electric power. As seen from FIG. 5(b), the amorphous photovoltaic cell 1 is constructed of a metal substrate such as stainless steel substrate 2 which serves as a lower electrode, a PIN-junction diode 3 which is formed on the stainless steel substrate 2, a transparent upper electrode 4 which is formed on the PIN-junction diode 3, and collectors 5 which have a configuration as shown in FIG. 5(a). Such an amorphous photovoltaic cell 1 is produced using the stainless steel substrate 2 which has been cut into predetermined dimensions beforehand. Symbols 2a denote parts of the stainless steel substrate 2.
FIG. 6 is a view showing the arrangement and connection of the amorphous photovoltaic cells 1 in the power-generating amorphous photovoltaic-cell module which has been fabricated using the large number of amorphous photovoltaic cells 1 as illustrated in FIGS. 5(a) and 5(b).
An amorphous photovoltaic-cell module illustrated, by way of example, in FIG. 6 consists of the amorphous photovoltaic cells 1 in four columns and twelve rows, totaling forty-eight cells. The amorphous photovoltaic cells 1 in the two righthand columns and those in the two lefthand columns are arrayed facing directions opposite to each other. Thin rectangular ribbons 6 called "tab leads"are used for connecting the collectors 5 and the parts 2a of the stainless steel substrates 2.
Next, the method of electrical connection among the forty-eight photovoltaic cells in FIG. 6 will be explained. In forming the amorphous photovoltaic cell 1, the stainless steel substrate 2 has its parts 2a shielded by a mask (not shown) in advance so as to prevent the PIN-junction diode and the transparent upper electrode from being formed thereon. Accordingly, the parts 2a of the stainless steel substrate 2 and the collectors 5 have opposite polarities.
In the module of the amorphous photovoltaic cells for power generation thus constructed, the amorphous photovoltaic cells 1 at the heads of the two righthand columns or the two lefthand columns are connected in parallel by the ribbons 6, and the amorphous photovoltaic cells 1 of mutually opposite polarities adjoining in the vertical direction are successively connected in series as depicted in FIG. 6. Among the four amorphous photovoltaic cells 1 at the lowermost end, the two located centrally or the two located on both the outer sides are connected in series. Thus, two series paths are connected in parallel. Therefore, the amorphous photovoltaic-cell module is constructed so as to derive an electric output across the terminals thereof marked + and - when the surfaces of the cells are irradiated with light such as sunlight.
Unlike a single-crystal cell or a polycrystalline cell, the amorphous photovoltaic cell can advantageously be produced into as a large area element by, for example, the plasma CVD process. Since, however, an amorphous photovoltaic cell is a constructed from a thin-film, a large area cell cannot be made to have a large current flow therethrough. For this reason, metal substrate type amorphous photovoltaic cells and the module of the cells in the prior art are constructed as described above, and a large number of amorphous photovoltaic cells must be arrayed and connected by the ribbons. This has incurred the problem that much labor and time are expended in assembling the amorphous photovoltaic-cell module.